No act or omission done or suffered by or on behalf of the Crown constitutes an offence under this Act; but the Court of Session may on the application of a public authority or office-holder responsible for the enforcement of anything required to be done, or prohibited, by or under this Act, declare unlawful any act or omission so done or suffered.

A planning authority must not take any step for the purposes of enforcement in relation to Crown land unless it has the consent of the appropriate authority.

The appropriate authority may give consent under subsection (2) subject to such conditions as it thinks appropriate.

A step taken for the purposes of enforcement is anything done in connection with the enforcement of anything required to be done or prohibited by or under this Act.